The consumer is presented with a wide variety of choices to enhance his home or office telephone system. If the consumer does not wish to be limited by the length of a telephone cord he can purchase a cordless telephone. This will provide the consumer with a roaming range of about 50 feet. If this is inadequate, the consumer can buy a cellular telephone to provide a virtually unlimited roaming range. However, the extra cost for cellular air time dictates that most consumers have a cordless telephone for their home and cellular telephone when they are away from home.
The consumer can further enhance his phone service by having additional phone lines coming into his house. In this way he can receive or place two phone calls at one time. This also allows the consumer to place a call to a second phone in his house. Unfortunately, the cost of adding a second phone line is non-trivial. Alternately, the consumer can have multiple phones connected to the same phone line. This solution does not allow the consumer to place a call from say the basement phone to the second floor phone.
The consumer can purchase an answering machine, which will automatically answer the phone when consumer is not at home or does not want to be disturbed. Answering machines are limited, in that a person wishing to leave a business message for one member of the household cannot ensure that it will not be heard by another member of the household. In addition, every member of the family has to listen to all the messages to find out if any of the message were intended for them.
Phone companies and others provided voice mail systems where messages can be left in individual mail boxes. These mail boxes can be accessed individually and often require an access code. While this solves some of the problems inherent in answering machines, the companies charge a monthly fee that adds up over time.
A speaker phone is another device a consumer can add to enhance his phone service. Speaker phones allow hands free operation of the phone, which can be helpful when looking over and discussing documents or for conference call capabilities. Speaker phones experience feedback from the speaker to the microphone, unlike conventional handsets. This has been solved by having a signal activated switch which only allows either the speaker or the microphone to be working at any one time. This is known as a half duplex system. Even though the switch works automatically it does not allow for the free flowing conversation of a standard telephone.
Thus there exists a need for a system which can solve these and other problems encountered in home telephone systems.